This invention relates to a valve, particularly a pressure relief valve for a lubricating oil filter of an internal combustion engine, which valve comprises a valve plate, a valve body which cooperates with the valve plate, a valve spring, and a valve hood, in which the valve spring is supported on the valve hood and exerts a force against the valve plate to seal the opening between the valve plate and the valve body, and in which the valve body has a bead margin at the end facing the valve seat and the valve hood is crimped under this bead margin.
German utility model no. DE-G No. 18 95 630 discloses a fluid filter for a motor vehicle hydraulic system which has an overflow valve. This valve consists of a valve plate for which a valve seat disk is provided, which is joined to a housing by crimping. An open-sided valve hood is attached to this valve seat disk, and a valve spring acting on the valve plate is supported on this valve hood.
Such valves generally serve to maintain oil circulation when the oil filter is too heavily clogged and in need of replacement, at which time the valve opens at a certain oil pressure which occurs under such conditions. The valve described in this German utility model is completely crimped onto the housing of the filter, so that if the valve becomes defective or when maintenance operations are necessary the valve cannot be replaced. Furthermore, the valve seat is formed by the valve plate on the one hand and a valve seat disk on the other, which is a crimped piece of sheet metal. In this kind of construction there is a danger that, if the valve seat disk is not completely flat, the valve will be leaky even in normal operation, so that dirty lubricating oil can reach the clean oil side of the filter.
German utility model no. DE-G 90 10 459 discloses a valve which avoids the above-described disadvantages and assures a reliable sealing of the clean oil side from the dirty oil side. In this valve, however, it is necessary to have a crimped-on valve hood which is designed to support the valve spring and to guide the valve plate.